Change filecheck default to dump input on failure

Having the input dumped on failure seems like a better
default: I debugged FileCheck tests for a while without knowing
about this option, which really helps to understand failures.

Remove `-dump-input-on-failure` and the environment variable
FILECHECK_DUMP_INPUT_ON_FAILURE which are now obsolete.

Differential Revision: https://reviews.llvm.org/D81422

GitOrigin-RevId: d31c9e5a46ee692daf2430b52626afcea1db18ab
diff --git a/llvm-prettyprinters/gdb/llvm-support.gdb b/llvm-prettyprinters/gdb/llvm-support.gdb
index cdd3388..6ae1c70 100644
--- a/llvm-prettyprinters/gdb/llvm-support.gdb
+++ b/llvm-prettyprinters/gdb/llvm-support.gdb
@@ -1,4 +1,4 @@
-# RUN: gdb -q -batch -n -iex 'source %llvm_src_root/utils/gdb-scripts/prettyprinters.py' -x %s %llvm_tools_dir/check-gdb-llvm-support | FileCheck %s --dump-input-on-failure
+# RUN: gdb -q -batch -n -iex 'source %llvm_src_root/utils/gdb-scripts/prettyprinters.py' -x %s %llvm_tools_dir/check-gdb-llvm-support | FileCheck %s
 # REQUIRES: debug-info
 
 break main